1. Field of the Invention
The present invention belongs to the field of an audio signal processing, particularly a technology of generating a surround signal having reflected sound and reverberant sound.
2. Discussion of Related Art
In a conventional technique, there is known an art of SFC (Surround Field Control) for simulating an acoustic field image that is realistic and spatial by adding the reflected sound and reverberate sound (reverb) to the audio signals of music, movie and so on.
In a surround circuit disclosed in Patent Document 1 (Refer to FIG. 1), as an example of these arts, surround signals LS and RS are computed from audio input signals of left channel (Lch) and right channel (Rch). The surround signals Ls and Rs are respectively attenuated in an attenuation circuit, subsequently added by left and right audio input signals respectively in an adder circuit, and outputted. Thus, surrounding effect sound is generated to the listener. Patent Document 1: Japanese Unexamined Patent Publication No. 2000-102100